A home made effective "waterless urinal"

An Effective (and stink free) urinal

Yes I know, this is a subject not very high on peoples list of things to read about, but it is important nonetheless. It gets old, especially in the morning, being a coffee addict, going to the house every time I needed to do #1. Also if you know anything about "camp hygiene", you know that you should be away from your living area when disposing of any bodily waste.

 

I am sure that the men reading this (maybe not so much the women), have seen a "waterless urinal". In these there is no flushing required. When I first encountered one, I was intrigued by the fact that there was no "smell" associated with them (I have since discovered some that, due to maintenance issues, or lack thereof, do smell). I set out to find out how these worked.

 

The principle itself is actually VERY simple. As long as a layer of oil sites on top of the urine, the smell is blocked. This is the very basics of its operation and anything more is simply so that somebody can "make a buck" off of it. There are also companies that sell "magic, secret formula, oil" for use in these toilets. I found that simple ordinary "baby oil" works very well and even smells nice. I do not recommend vegetable oil, because of the smell of the oil itself.

 

Some may ask, "why a urinal and not just a composting toilet?". Well the answer to that is that after reading about composting toilets, they do not work well with too much liquid. Those must be kept relatively dry to function properly. There are even composting toilets that have a "diversion bottle" for urine because of this.

 

So I set about designing my own unit to test if this principle really does work. My requirements were, a storage bucket, a large "target", and something that would not require a large amount of oil each time it was emptied. So Off to Home Depot again for the "ingredients".

 

 

I used a Home Depot bucket and lid for the main container. I then inserted an internally threaded "bulkhead connector" in the lid. This has a single thread on the outside to screw it tight, and a "pipe thread" in each end of the connector. It is usually used to run pipes through a panel and provide a joint on each side.

 

To this I added a PVC "dip tube" with an end to thread in to the bottom of the bulkhead connector. The dip tub runs down to the bottom of the bucket (as close as possible). You can also notice that I cut grooves in the bottom of the pipe for the liquid to flow out. To the top I added the adaptor for a funnel I found at Autozone.

 

Here is the end result. Just the right height for average sized men, and possibly women (although no woman has had the need to test THAT theory :-)

 

 

To put it in to service, I put water in the bottom enough to where I know the level is above the grooves in the pipe. Then I put in the layer of baby oil. Due to the fact that the oil is lighter than water, it stays in the pipe and does not flow out in to the bucket. The only other required "accessory" is a spray bottle of baby oil to occasionally "flush" the "funnel". Just a mist around it is sufficient.

 

Now for the big question, DOES IT WORK?!



With it sitting close to my desk, it was time to put the theory to the test. Day after day, I used it as much as possible. The days became a few weeks and still I could smell nothing (after a while, not even the baby oil). I thought maybe I was simply "getting used to the smell". Then I had to leave for 5 days (with everything off, including the air conditioner) with everything closed up. I decided to intentionally not "service" the bucket to see what would happen.

 

Upon my return, there was no trace of smell. If there was going to be, it would have been during this time of high heat and no air flow in the box. From here, it could either be one of two things. Either my urine doesn't stink ;-), or the idea truly worked. It was time for the final test, it needed emptied.

 

The moment I popped off the lid, I learned that my urine does indeed stink! :-) The smell that came out, convinced me that it needs to be emptied before it is actually full. I think I would rather have been sprayed by a skunk than what I encountered. Either way, this experience left no doubt that this design does indeed work.

 

The only thing I would change in the future is to "JB Weld" a larger diameter pipe in to the bottom of the bucket as a guide for the dip tube. One other thing is a means to empty it where I do not have to remove the lid!

Moving day

How NOT to move your container :-)

Last Sunday I finally decided that with nothing else productive to do, it was time to move the Box in to place by the new container. The "end goal" is to possibly link the two together in an "L" shape. I feel this is a good time to make some notes about what to do and what NOT to do when moving or even leveling a container.

 

This was the first time that it had been moved since I built it. During construction it was already in place and leveled before any cutting had begun. With this move, I had windows and drywall and everything else inside. My biggest fear was breaking windows by "tweaking" the box as I lifted each corner. Another concern was the previous location was on a slope and the new location relatively flat.

The actual "move" was only 8-10 feet in one direction but what an adventure it turned out to be!

 

Since I don't have anything to actually lift and move (like a large forklift or a crane) the only option available was to slide it in to position. For this I put two sections of well casing under it and then slowly set the box down on the well casing. From here I then used my truck to pull it down a little bit at a time, alternating corners as I went to try to keep it straight.

 

This brings up my first point I need to drive home to anybody dealing with containers. NEVER underestimate the weight of a container!!



 

 

The picture is one of the 2 pieces of 3 1/2 in well casing I had under the box to drag it on. Before I started it was STRAIGHT. I will in the future be shopping for I-beams for any future moves!

 

Moving on, even with the doors open I remain amazed at the rigidity of these things. There was no noticeable bending or "tweaking of the structure. It remained a perfectly square box for all intents and purposes. There was no damage to the windows either.

 

Leveling and lifting

Here is where you begin to wish that it was not so rigid. for this I use a normal high-lift jack and a purpose built hydraulic container jack of my own design. Now that I know my design works I need to build another one. A word of caution is in order here, DO NOT EVEN THINK ABOUT USING 1 JACK TO LIFT A CONTAINER! At a MINIMUM, have 2 high-lift jacks on hand before you even begin.

 

Before you even begin lifting any more than 1/2 inch or so, make sure all corners are in contact with the ground. "shim it" with blocks, gravel, sand, 2x4's or anything else to begin with all 4 corners in contact with the ground. If you do not do this you have a very big chance that it will come up with most of the pressure on one corner. If this happens it WILL "pivot" on that corner at the most inopportune moment!

 

Now that you have equal pressure under all four corners (as close as possible) you can begin to level. For this you will use your jacks either both on the end, or both on the side. If you do not have an "inclinometer", then measure your starting points. A bubble level may be no good because if it is too far off you will not see how far it has moved.

 

Now you are ready to lift. This is NOT the time to get in a hurry! Bring one jack up 1 "click" and then bring the other up one click. Get out your tape measure again and verify that it came up evenly (be very cautious about the jack settling in to the ground!). At this time inspect the non lifted corners to ensure that they are still firmly on the ground. Repeat this "1 click at a time" until you are level on 1 side. After blocking and removing the jacks, you can now go to the low end and repeat the procedure.

 

Once you are level, then you can move on to set the height using the same procedure.

 

Summary

• Do not ever let all the pressure rest on 1 corner at any point in the lift! Either the two side corners on the ground, or the two end corners.
• Lift evenly on the side or end. Constantly inspect the non lifted corners for indications they are coming off the ground.
• DO NOT GET IN A HURRY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 



"Hot" water coming next

Well I got ahead of myself a bit. Found a deal on a tankless water heater that was just too good to pass up.

Here is the unit I bought Fastar 8L per minute LPG tankless water heater. If the link goes dead just search ebay on some variation of that description.

For my American readers, let me first explain a bit about how tankless water heating systems work. There is no "holding tank" like we are used to. Water is heated as it flows through the unit. Whereas a tank type water heater keeps the water at a constant temperature, a tankless works on "temperature rise". In other words instead of hot water being held in the tank at 170 deg/F, a tankless raises the temperature of the incoming water by "X" degrees. An example of this is that when I tested my unit, Incoming water was about 55 deg/F. At full flow my "hot water" was about 100 deg/F after going through the heater.

The temperature of the water being output can be raised by slowing the flow of the water through the unit. This allows the water in the system more time to absorb heat. Bottom line, less flow, hotter water. There are safety features built in to all tankless heaters to prevent the water from boiling. Some units include a temperature sensor that shuts down the burner if the water gets too hot (due to low flow). On this unit, the "safety" is a flow switch where the burner and the control power are shut off if there is no flow.

The control shutoff feature on this unit was a welcome surprise. Because the burner control runs on 2 D-cell batteries I had some concern about battery lifespan if I forgot to shut it off at the provided switch. This unit conserves the batteries by shutting it completely off when the water stops flowing. The other safety feature is that, on the unit itself, the water valve can only be turned down so low. As long as there is water coming in, you cannot shut off the water at the unit with the provided valve. To completely shut off the water you need a valve on the input side of the unit. Shut that valve off and the unit will shut down completely.

The Fastar unit

There are a total of four controls on the unit itself. These are

• Summer / Winter setting
• This seems to be a "high low switch" for the burner.
• Burner gas control
• Can be used to adjust the amount of gas being consumed by the burner. This will also have an effect on the temperature rise.
• Water flow control
• Amount of water flowing through the unit. If you are at max burner level and the water is still not hot enough, you can lower the flow with this thus increasing the temperature of the delivered water. Simply be aware that you cannot shut off the water with this valve (as a safety precaution that I outlined above)
• Electrical on/off rocker switch
• Bypasses the flow switch to keep the burner from coming on even if water is flowing through the unit.

Test and evaluation of the unit

I set up the unit outside to test its operation and find its possibilities. First off you need to be aware that it is a design for the European market where tankless heaters are VERY common. The one thing that you will need to do if you purchase this unit or any others like it is to buy adaptors for the fittings. Be aware that for pipe this size, most European systems us "BSP" or "G" threads. this is a straight thread used for gas and water. These fittings you will not find at "Home Depot" so plan on ordering them when you order your unit (or any other unit that has "BSP" or "G" threads).

What I found was Conversion Coupling Adaptor To Convert USA 1/2" NPT Male To 1/2" BSP Female on Ebay. These fitting came "overnight" from England via FedEx. Once these were in place I was able to use Home Depot for the rest of my fittings. Be aware to will need a 1/2" female NPT to flared fitting adaptor for the LPG connection. I only had one LPG appliance which was a space heater so I decided to "standardize" on that (3/8 FL connection). I recommend that all LPG connections in your household be the same so that if you have a regulator go bad, you are not "stuck" until you can buy a new one.

So now that I had all my fittings it was time to test the unit. Here is a photo of it all set up for testing with a garden hose attached

Here you can see the Gas, incoming water, and outgoing water (shower) connection. The shower was not all that impressive. It is better than a cold shower however :-) Do not plan on using a conventional shower head with it as they are designed to flow at 2 1/2 gal/min.

The round thing on the right is the "indicator panel". When the control is on (water flowing and power switched on) it shows that water is flowing, burner is firing, and the temperature of the outgoing water. The only "inconvenience" is that it gives temperature in deg/C. I classify it as an inconvenience because who really monitors the precise temperature of their shower or bath?

With everything hooked up I fired it up for the first time. Everything worked perfectly and operated just like any other tankless heater. Water started at 11 deg/C and went up to 36 at full flow and burner. Backing off the flow where you could still "shower" with it, the temperature went to ~40 deg/C.

Overall impressions

I cannot at this point speak about long term reliability. That will be a wait and see matter. One nice thing is that it is self contained and can be used anywhere. This makes it great also for a camper. with a bit of plumbing, you have hot water at your sink and a warm shower. From what I have seen so far, I would not recommend a unit of this size for household use except over a sink (and a shower in a pinch). For that I would recommend at least a 4 L/min unit so you can also use the shower more effectively.

One thing I am also looking at this unit for is Hydronic heating. If you put a 2 gpm pump inline with it and then PEX tubing under your floor, it could be used to heat your space. Simply tie the pump to a thermostat for heat. I would also recommend a temperature switch in the return line. Pump comes on, heater fires and warms the water circulating in your floor where the heat rises into your space. At this point that looks like a relatively easy way to heat even a home. Please keep in mind however as at this point this is simply me thinking out loud :-)

"Bottom line"

I would highly recommend this unit for a cabin or camper. For a home (if you only do "showers") buy a unit that is capable of at least 4 gal/min.

Water (part 3b) Filtration assembly

Now its time to put it all together. I will begin with the holding tank modifications.

On the tank you can see three changes.

• I added a coupling to the tap to the filter unit. This was done so that I can easily connect to another water source.
• Added a return line. This is a water return for the RO filter. It is also "Tee'd" at the filtration/pump unit so that I can bleed air out of the system. The ability to bleed out air was something very important that I overlooked in my original design. DO NOT MAKE THE SAME MISTAKE I DID AND OVERLOOK THIS!
• At the cap is the hose coming from my aquarium aerator pump. This goes to a large air stone in the bottom of the tank. I cycle this a couple times a week to keep the water "fresh".

Now on to the actual handling unit. One note here, the handling unit is not "neat and tidy". It is still a "work in progress" but the basics are there now.

Water from the tank comes directly in to the pump via the 1/2 inch line. The pump then goes directly up to the manifold on top. The copper riser on the gauge is there for dampening the gauge. Before I installed that the first water pressure gauge actually shook itself apart. This is a "problem" with high pressure diaphragm pumps. They can "hammer" quite severely each time they cycle.

The first ball valve feeds the filter unit. The second ball valve was originally to feed a sink with the same pump. Its main purpose now however is to "bleed air" out of the pump intake line and the filters. In the photo, you can barely see the "Tee" I mentioned earlier on the return line to the tank.

You can use the bleed valve for two conditions.

• The first is when you get too much air in the intake line. If this is the case, you will hear the pump running "fast" and not actually pumping water or see that there is no water in the intake tube at the pump.  At that point, open the bleed valve completely until most all of the air has been pumped out of the line.
• The second condition is with initial commissioning or changing filters. You will know there is air in your filters by frequent cycling of the pump. The other indication is the pump running close to full speed and then slowing as it approaches its pressure set point. The best thing to do after you have changed the filter or are commissioning the system for the first time, is to simply "crack open the valve" and let everything run until you see only water coming out of the return line. Your pump will tell you by the way it behaves if you have air in the system.

So to summarize, if the pump does not draw in water, open the bleed valve all the way until it does. If you are commissioning new filters then simply "crack it open" a bit to give the air someplace to exit the system. Also, always mount your "bleed" at the highest point on the system. This allows the air to "rise" out of the system.

Now we look at the cabinet.

Here you can see why I recommended the "all in one" unit in the last paragraph of the last posting. The only thing you cannot see is the UV unit behind the pump. It is tie wrapped to the filter bracket. One other thing to keep in mind, if you will notice the little black box on the right. This is the ballast for the UV unit. Keep this someplace where you can see it. There is an LED on this box. This LED indicates that the bulb is ok and working.

One thing I cannot stress enough is treatment for parasites and bacteria. KEEP THEM OUT OF YOUR FILTERS! I would recommend keeping on hand unscented pure bleach. If for some reason the UV sterilizer goes bad, and you do not have a replacement bulb, then pretreat the incoming water with the bleach. It will be a bit harder on your filters, but in a pinch it is a whole lot better than getting sick!

Here is a site from the CDC that gives water information including instructions for disinfecting with bleach.

 

http://www.cdc.gov/healthywater/emergency/safe_water/personal.html

 

If you have to resort to this, you can use the pump to "mix" the bleach in your holding tank. To do this:

• Add the proper amount of bleach to the holding tank.
• close the valve to the filters
• open the bleed valve
• turn on the pump
• Run the pump long enough to completely recirculate the water in the tank 2-3 times

On my unit, I assume I am only pumping 1/2 gallon or so a minute. I have a 30 gallon storage tank. I wish to run this water through the pump twice. that would give about 30 gallons per hour. With this in mind, if I run my pump like this for two hours my water should be thoroughly mixed (especially since I "draw" from the bottom and return to the top). When finished the chlorine will be removed again in the filters. I would also recommend that during this time and for a day afterwards you do not run the aerator (this will "dilute" the chlorine).

 

If there is any interest, I will add a post with the actual plumbing diagram.

Water (part 3a) Filtration components

It's finally complete. I now have the capacity for 30 gallons of water in the Box. From this I can either use it directly, or for drinking, divert through a reverse osmosis filter system and tap directly from the pressure tank. Unfortunately, it turns out I did a LOT more work than I needed to. More on this later.

The system as it exists now, is also suitable if you are wishing to prepare for an emergency water source. As I wrote earlier, CLEAN WATER is most likely the single most overlooked item (or "understocked" item) on any list of emergency supplies. If you live in a tornado or other area where natural disasters can occur, then you may want to take a close look at this for daily AND emergency use.

All of my components were from Ebay and after fixing the "leaks due to loose hoses and fittings" seems to be working very well. First the components of the handling and filtration system. I am including a link to the "auction" along with a photo of the item. Be aware that at some point however the link may go dead.

First up the UV "disinfecting" unit. As far as I am concerned, this is most likely THE single most important item in the system. Although I have not done so, I would recommend this come even before the pump (and be "sized" for the flow rate of the pump). The reason for this is if you use water directly (bypassing the filters), you will at least kill any bacteria in it first. This in line with the "sand filter" I built should be plenty "clean" to at least shower with or wash dishes and general cleaning. Here are some links to UV water treatment:

http://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation

http://www.harvesth2o.com/uv.shtml#.VSVTEWd0ypo

www.water-research.net/Waterlibrary/privatewell/UVradiation.pdf

This and more information can be found by entering the search term "uv water treatment". Be aware that all of these units I have seen so far need a source of AC power to operate. More on this later.

Here is the unit I bought

http://www.ebay.com/itm/UV-sterilizer-Water-filter-1-gpm/221738767484?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D777000%26algo%3DABA.MBE%26ao%3D1%26asc%3D20131227121020%26meid%3D13ab1316b522498185138dcc157437c6%26pid%3D100009%26rk%3D1%26rkt%3D1%26sd%3D391108662057

This is a 1 gallon per minute unit that works fine inline with my RO system.

Next the pump. Here is what I have

http://www.ebay.com/itm/181392820089?_trksid=p2057872.m2748.l2649&ssPageName=STRK%3AMEBIDX%3AIT

This is a 100psi ~1 gallon per minute (4 Liter/min) pump. A diaphragm pump is important firstly to reach the pressure necessary for the RO filter. One note I should make here is that this pump regulates pressure with a spring loaded switch. I had A LOT of problems with this working correctly. It was inconsistent in shutting off at the 100 psi. Also if it went over pressure, it leaked. After much trial and error, I finally "tuned it" to where it would shut off at 70 psi, and turn on at 60 psi. Also something that should be noted with this pump is that the feet are in a dovetail. I first mounted it with the pump head up. This resulted in the pump vibrating out of its feet. I recommend mounting it horizontally or with the pump head down to prevent this.

Now I encountered a slight problem. The pump is 12 volt DC and the UV sterilizer is 120 volt AC. Since a sterilizer is not readily available for 12 volt DC power, and I want to use a single power source, I had to buy a power supply for the pump. Since the pump is 12 volts and draws 3 amps full load, this means I need a power supply capable of 36 watts (volts x amps = watts, when dealing with DC).

For a power supply I got this

http://www.ebay.com/itm/371117456686?_trksid=p2057872.m2749.l2649&var=640277552001&ssPageName=STRK%3AMEBIDX%3AIT

The unit I bought has a 3 amp output. One of the surprising things I found about this particular unit is that it is "current limiting". This means it will not put out more than 3 amp. This also means there is no reason for a circuit breaker on the DC side. It can also take a wide range of AC power in both voltage and frequency. One added benefit of it is that it does not come on immediately. The reason this is an advantage is that it allows the UV light to come on before the pump comes on (ensuring ALL water that passes through the system is treated properly.

Lastly is the filtration unit itself

http://www.ebay.com/itm/140464920711?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I could find no rating for "gallons per day" output, but I assume from using it is somewhere in the 50-100 range. The most important feature of THIS system is the pressure tank. Because of this I can pump the tank full and then turn off the power and still have flowing water at the tap (until the tank is empty).

One last item you should have in case of power outage. A small inverter is wonderful to provide the power you need for the system from a car battery. I have this unit as a backup if the need should arise

http://www.harborfreight.com/200-watt-continuous400-watt-peak-power-inverter-61478.html

200 watts is fine for running the pump power supply and the UV filter. Keep in mind however that, if you are running ANY inverter from a car battery, do not drain the battery very much. Car starting batteries are not made to "deep-cycle" (which means draining it to almost empty and then recharging it). The best way to operate using this method is to run the vehicle engine while the inverter is running. A 200 watt inverter should be able to take all its power from the alternator while the engine is running.

In the next section I will go in to detail and photos of how the whole system is put together. Before that however, you get to benefit from my "mistakes". After I had assembled everything and had it working I found THIS on Ebay

http://www.ebay.com/itm/Reverse-Osmosis-Ultraviolet-Sterilizer-Water-Filter-System-UV-RO-6-Stage-100-GPD-/261561736325?pt=LH_DefaultDomain_0&hash=item3ce64b5c85

This unit has everything you need except for the pump (and components associated with the pump). It will save a WHOLE LOT of work plus you get 3 additional pre-filters and a "handy-dandy" rack. With this you could build the entire system in to a "hard case" and be completely portable. Oh well, "live and learn".









 

Water Part 2 (storage)

Next up is the water storage system. Space being an issue, I decided that 30 gallons would be a good quantity to keep available for direct use. This will be stored inside so that there are no issues with freezing.

My requirements for a storage container are not only that it is clean and strong, but also that I can empty and clean the tank of and sediment that may make it in to the tank. For this I chose a 30 gallon removable top barrel. This unit is HDPE and has a ring lock with a gasketed lid and NEW not recycled or "cleaned out". the only thing I don't like is it is, of course, blue.

The "bungs" on this drum accept 3/4" pipe and 2" pipe fittings. As you can see, there is a fitting that I already made to both fill and draw from it. the fill/drain assembly is a "dip tube". The tube goes down about 7/8 to the bottom. A word of caution here. DO NOT run the pipe all the way to the bottom. Yes you loose a bit of capacity, but you gain a settling space for anything that makes it through the filter and is heavier than water. Another note along these lines. Unless you are putting in only 100% potable water, do not drain to the bottom of the dip tube. If you do anything lighter than water that separated during storage will be drawn in to your water supply. For now I simply go by visual for the water levels. Later I am hoping to add a controller to monitor the level.

On the threaded fitting for the dip tube some minor hand work was require with the threaded adapter. As with the PVC, there is a lip in the threaded adapter to keep the tube from going all the way through. Out came the Dremel tool and the lip was ground away until the tube slipped through it.

In this photo, you can see the two valves. The valve on the left is for filling, and the valve on the right is for the delivery. To fill simply attach the water source, close the delivery and open the fill valve. When it is full close off the fill valve and open the delivery valve.

There is one detail with this that is not obvious. The valve on the left has a drain cap and is installed backwards. The reason for this is to allow the fill line to drain after the hose is removed from the outside. As I stated earlier, my fill line will run to the ceiling, across and out and back down to a tap on the outside. When I am done filling that line needs to be drained of water or else two things can happen. First is the line may freeze. More importantly though, if the outside tap is opened, the tank will be drained by siphon effect down to the level of the outside tap (about 3/4 of my water).

To prevent this, I first open the outside faucet and then crack open the cap on the valve to allow the water to be sucked back out of the line. In this way, the line is empty and i don't have to worry about freezing.

If at some point I wish to add more storage capacity, I simply need to add barrels and connect the valves to a manifold. The same thing can be done with 55 gallon barrels. Either way, I recommend open top barrels because eventually they should be cleaned and sanitized.

The next installment will begin to cover the "real" filtration system.

Water, part 1 (Introduction and pre-filter)

WATER, the single most important necessity in life. With modern convenience however it is the most overlooked requirement for living.

For the last year, I have simply used a 5 gallon jug of water with a hand pump. It is time however that I begin installing a more permanent water supply with greater capacity. As I stater earlier, during construction I installed a pipe in to the wall to bring in water from an external source. The original plan was simply to connect a hose from the house to fill a tank.

The more I thought about this however, the more I wished to make a more versatile water system. As I have lived and worked with the box, I have developed a desire to have the unit self contained. This goes back to the "portability" advantage of working with a container. The "easy" way is simply to continue with my original plan and use the house as my water source. This will require though a constant source of potable water being brought in to the box wherever it may be located. Not a very good plan if I should decide to move it to some sort of "unimproved ground".

With this in mind, I have decided to build the system with the ability to handle water from almost any source. My "ideal" would be to pump water from the source (be it a pond or stream) in to a wheeled tank and then bring it to the box for treatment and storage. Using this method and this type of water source can be dangerous to your health!!!! I personally have had food poisoning once in my life 30 years ago. I still remember it clearly and do not ever want to go through it again! It is from this perspective that I design my system.

There are multiple issues at play here and all must be addressed in any system such as this. The issues are as follows:

• Chemical contamination
• Solids removal
• Bacterial contamination
• Removal of larger organisms

Some of these are not a big issue depending on the end use of the water. Because of this I have divided my needs between "general purpose" water (washing, cleaning, toilet usage) and potable water (drinking cooking). In both "types" of water the "general" requirements are the same as outlined above. Drinking and cooking water however are a "take no chances" affair. This water MUST be as pure as humanly possible. 

So, with all of the above we begin to design the system. Course filtering and chemical separation are first up. This is the only thing I built rather than bought off-the-shelf. What I wanted was a filter able to be "renewed" with natural available materials. I also wanted it to function so that lighter contaminants would stay on top of the incoming water and the heavier contaminants would settle to the bottom. The end goal is to have relatively "clear" water exit the prefilter. 

Prefilter construction

I built the prefilter from PVC pipe. It is designed so that water has to travel down through a filter medium before returning back up to the exit. The less flow through this filter, the more likely light chemicals and contaminants will simply float at the top of the of the filter. At the same time the heavier contaminants will settle to the bottom. I started with the following pieses of pipe and fittings

What you see here are all of the pieces prior to assembly. The assembly itself is simply a "pipe within a pipe". For this version I have a 3" outer and 2" inner pipe. There are only 2 modifications that have to be done besides gluing everything together.

The bottom of the inner pipe needs to have slits cut in it to allow the water to flow through. For this I used a saw blade on the vibrating tool seen also in the picture. Once this is complete, the end cap can be glued to this pipe. I was lucky with my cap in that there was a ring molded in to it that came pretty close to centering the pipe in the 3" cap. Note, it is imperative that the end of this pipe be cut square! If it is not, then this pipe will tilt and final assembly become very difficult.

The next and last modification is the hardest part of the whole project. The collar to support the inner and outer pipe together must be modified so that it will slip down the length of the inner pipe.

Looking inside you can see the "lip" that prevents the inner pipe from going all the way through. This lip must be removed. Care must be taken though not to cut too much out of the wall of the fitting or to damage either of the bores where the pipe will be cemented. I actually had a lthe where I could remove this ring. You could however use a Dremel tool, file, die grinder or any other method you should choose. Keep a short section of the pipe that will pass through here to test fit as you go.

Here is the end result looking from the 3" end. The 2" pipe will now pass completely through.

From here, I first glued the 3" outer pipe in to the cap that the 2" pipe was already cemented to. The next step is to cement up the "T" with its fittings for the outlet. The choice is yours if you wish to put the reducer on at this point (I did). Now it is a good idea to have a section of 3" pipe cut and ready to drive the assembly down the 2" pipe with a mallet. Drive it down to where it just begins to make contact with the 3" pipe. Now put cement around the 3" pipe and drive it the rest of the way down.

As long as there is no pressure on the outlet side, it is not really imperative to cement the 2" pipe in the adapter. In a non pressurized delivery system, the collar serves the purpose of "supporting" the inner pipe more than it does sealing it. however if you wish to have the outlet side under pressure, simply measure the offset between where the inner and outer pipe will come to rest when assembled. Apply the cement and then drive it home. This should allow you to operate the whole thing under pressure on both inlet and outlet.

Here you see the finished product. The last PVC fitting to be installed is the threaded connector on the end of the 2" pipe. I want to add that I used a 2" threaded coupling so that the whole thing can be easily filled and emptied. To put it under pressure you will need to make some sort of adapter to screw in to this 2" coupling.

I made this so that I could attach a garden hose for testing purposes. The brass fitting is screwed in to a 3/4 pipe adapter.

On my first trial, I put a layer of course gravel in until it was above the slits I had cut in the inner pipe. I then filled it the rest of the way with general purpose sand from Home Depot. In testing I found that at household pressure and a 2" column of sand, I was flowing approximately 1/2 gallon per minute. For my needs, this is far too little.I however replaced the sand with gravel all the way to the top. At that point, it flowed as fast as I could fill it and would even work under gravity. In the coming days I will experiment further with filler material.

Please keep in mind my intention with this. Its purpose is simply for pretreatment and to remove some solids, scum and oils. It is not intended to produce drinking water! Its purpose is to get more life out of the "higher end" filters down the line and keep sediment out of your holding tank.

In the next installment I will move on to the holding tank.